Thomas Mulcair says it was never his intent to spar with the leaders of the Western provinces as he blames Alberta's oil sands for the loss of hundreds of thousands of jobs in Canada's other economic sectors.

"I have far too much respect for provincial premiers or for provincial politicians, having been one myself for so many years, to ever want to be interpreted as trying to dismiss them," the Leader of the federal New Democrats, who was once a provincial cabinet minister in Quebec, said on Friday in an interview with The Globe and Mail.

"And if that is the way it was interpreted, of course," he said, "I regret it."

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But Mr. Mulcair continues to press his belief that allowing development of the oil sands to proceed without demanding a greater price for the toll on the environment is driving up the dollar and hurting a wide range of industries including manufacturing, fishing and forestry. New Democrats say that without the oil companies paying the true cost of environmental remediation, their profits are unrealistically high and that is driving up the dollar.

"This is the defining issue for the next election campaign in Canada, what type of country we want to leave to our children," Mr. Mulcair said. "I am convinced that Canadians are going to be with us on this one. But, you know what? For once, we are going to have a real political debate in this country on a substantive issue."

Mr. Mulcair has said Canada has a case of the Dutch disease – the situation in the Netherlands in 1959 when the discovery of natural gas increased the value of the country's currency and caused other industries to collapse.

Not everyone who has studied the issue agrees. But Mr. Mulcair was not the first to suggest that Canada has lost jobs as a result of a thriving resource sector. Ontario Premier Dalton McGuinty has made that claim. So has the Organization for Economic Co-operation and Development.

A research paper that was funded by the Harper government and is about to be published in a prestigious journal, Resource and Energy Economics, concludes that a third or more of job losses in Canada's manufacturing sector can be attributed to resource-driven currency appreciation.

Mr. Mulcair said he has been advancing this theory for years. "So why is it coming up now?" he asked. "Well, the Conservatives have decided to make it an East-West debate."

The controversy is the first major test for the NDP Leader since he took the helm of his party in March – one that has put him in the crosshairs of the three Western premiers. Brad Wall of Saskatchewan accused him of ignoring the facts. Alison Redford of Alberta said his comments were "divisive and ill-informed." Christy Clark of B.C. dismissed his assertions as "goofy."

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Mr. Mulcair shot back that the comments from the premiers were merely Mr. Harper's attempts to "send in messengers to take that argument to me," an assertion that further infuriated the Western leaders.

The spat between the NDP Leader and the premiers has provided the federal Tories with a new message track that could easily become the central theme of attack advertising. All week long, Conservative cabinet ministers and MPs have been branding Mr. Mulcair as someone who is willing to pit one part of the country against another, a divider who would sacrifice the West.

Mr. Mulcair dismisses the accusations as the "bully" techniques of a government that knows it could not win a real debate about whether the resource sector is paying the true price of production.

"You realize that it's not a three-day debate, it's not a three-week debate, it's not a three-month debate, it's a three-year debate," he said. "We'll just keep coming back with what the real issue is. The real issue is polluter pay. People in Alberta believe that polluters should pay. People in Saskatchewan believe that polluters should pay. People in B.C. believe that polluters should pay. It's a consistent thing across Canada."

Gloria Galloway has been a journalist for almost 30 years. She worked at the Windsor Star, the Hamilton Spectator, the National Post, the Canadian Press and a number of small newspapers before being hired by The Globe and Mail as deputy national editor in 2001. Gloria returned to reporting two years later and joined the Ottawa bureau in 2004. More

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